This invention relates to the technical field of a guide plate assembly used to transport image recording media including a light-sensitive material having an image forming surface, in image recording apparatus, especially ones performing digital image recording with digital image signals, image readers including a scanner and processors (light-sensitive material processors) including a developing device, as well as an image recording medium transporting device using the guide plate assembly.
Heretofore, the image recorded on photographic films such as negatives and reversals (which are hereunder referred to simply as xe2x80x9cfilmsxe2x80x9d) has been commonly printed on light-sensitive materials such as photographic paper by means of direct (analog) exposure, in which projected light from the film is allowed to be incident on the light-sensitive material to achieve its real exposure.
A new technology has recently been introduced and this is a printer that relies upon digital exposure. Briefly, the image recorded on a film is read photoelectrically, converted to a digital signal and subjected to various image processing operations to produce image data for recording purposes; recording light that has been modulated in accordance with the image data is used to scan and expose a light-sensitive material to record a latent image, which is subsequently developed and output as a print (photograph). The printer operating on this principle has been commercialized as a digital photoprinter.
In the digital photoprinter, the image on a film is read photoelectrically and gradation correction and other operations are performed by subsequent image (signal) processing to determine exposing conditions. Hence, the digital photoprinter has many capabilities in image processing such as editing of printed images by, for example, assembling a plurality of images or splitting a single image into plural images, as well as color/density adjustment and edge enhancement; as a result, freely processed prints can be output depending on their use. In addition, the data on a printed image can be supplied into a computer or the like and stored in recording media such as a floppy disk or a hard disk.
A further advantage of the digital photoprinter is that compared to the prints produced by the conventional method of direct exposure, those which are output by the digital photoprinter have better image quality in such aspects as dispersive power and color/density reproduction.
Having these features, the digital photoprinter is basically composed of an input machine having a scanner (image reader) and an image processor and an output machine having both an exposing device and a developing device.
In the scanner, a reading light issued from a light source is incident on a film. The resulting projected light carrying an image recorded on the film is converted photoelectrically with an imaging lens in an image sensor such as a CCD sensor to read the image. The image is sent to the image processor as data for the image on the film (i.e., the image data signal). In the image processor, the image data from the scanner are subjected to specified image processing operations and the resulting output image data for image recording (i.e., exposing conditions) are sent to the exposing device.
In the exposing device, if it is of a type that relies upon exposure by scanning with an optical beam, the latter is modulated in accordance with the image data from the image processor and deflected in a main scanning direction as the light-sensitive material (photographic paper) is transported in an auxiliary scanning direction perpendicular to the main scanning direction, whereby a latent image is formed as the result of scan exposure of the light-sensitive material with the optical beam. Then, back printing is performed. In the developing device (light-sensitive material processor), the exposed light-sensitive material is subjected to development and other specified processing operations so as to output a print which reproduces the image that has been recorded on the film.
In the exposing device, whether it is in the digital photoprinter or an analog photoprinter that relies upon conventional xe2x80x9cdirectxe2x80x9d exposure, a virgin light-sensitive material is in the form of a magazine, i.e., a roll contained in a light-proof case. The light-sensitive material is withdrawn out of the magazine loaded in the exposing device and further transported for exposure and other necessary steps. In the conventional digital or analog photoprinters, the light-sensitive material being transported is not cut but remains a web as it is subjected to exposure, back printing, development, rinse, drying and other necessary steps and only after these steps are complete, the light-sensitive material is cut to individual prints of a specified length.
In contrast, digital photoprinters also have a particular need to perform exposure after a web of light-sensitive material is cut to sheets of a length corresponding to one print or using a light-sensitive material previously cut, as accompanied by compactness of the apparatus and substantial reduction in the initial and running costs (printers of this type are hereinafter referred to as xe2x80x9cimage recording apparatus of a cut sheet typexe2x80x9d)
In the image recording apparatus of a cut sheet type, the light-sensitive material is nipped by transport roller pairs and transported by a light-sensitive material transporting device through a pathway that is formed in such a way that both top and bottom of the light-sensitive material are restrained by guide plates. In the aforementioned image recording apparatus of the type that performs all steps from exposure to development on a web of light-sensitive material, the latter can be transported with a reduced sliding contact with the top and bottom guide plates in the transport pathway once it has been passed through the first transport roller pair. On the other hand, in the image recording apparatus of the cut sheet type, the advancing ends of the sheets of light-sensitive material have to be fed into successive transport roller pairs; as the result, the light-sensitive material is transported as it is guided by the sliding contact with the guide plates and this causes a problem in that the recorded image may be damaged by the sliding contact with the guide plates. This problem occurs more or less in the light-sensitive material transporting devices located not only in the image recording apparatus of the cut sheet type but also in analog type image recording apparatus, light-sensitive material processors such as a developing device, and also in image readers such as a scanner, as far as the light-sensitive material transporting devices as described above transport the light-sensitive material. The situation is the same whether the light-sensitive material used is in the form of cut sheets, a roll or a film.
As shown in FIG. 6, the guide plate assembly 100 is usually provided with ribs (linear bumps) 102 that are arranged at specified intervals in the direction parallel to the direction in which the light-sensitive material Z is transported (or the direction normal to the plane in FIG. 6), thereby preventing the adhesion of the light-sensitive material Z to the guide plate assembly 100 due to an environmental change, especially high-temperature and high-humidity. The ribs 102 on the guide plate assembly 100 contribute to decrease the contact area between the surfaces of the light-sensitive material Z and the guide plate assembly 100 so as to prevent the adhesion of the two members even in a high-temperature and high-humidity environment where the two members are readily adhered to each other. The light-sensitive material Z is thus easily nipped by the subsequent transport roller pair, to thereby enable its smooth transport. On the other hand, the ribs 102 on the guide plate assembly 100 present a problem in that the light-sensitive material being transported makes sliding contact with the ribs 102, thus increasing the chance of its surface being damaged by the ribs.
If flaws and other forms of damage occur during the transport, images of high quality cannot be recorded and the resulting prints will have only low commercial value.
The same problem occurs not only in the guide plate assembly and the transporting device as mentioned above used to guide and transport the light-sensitive material, but also in other guide plate assemblies and image recording medium transporting devices used to guide and transport image recording media having an image forming surface, as exemplified by copy materials, ink-jet recording materials and thermal recording materials.
The present invention has been accomplished under these circumstances and has as its first object providing a guide plate that is used to guide and transport a recording medium having an image forming surface without flaw, in an image recording apparatus, an image reader and a developing device performing various image reproduction processing including exposure, recording, development and reading, whether the recording medium is supplied from the magazine in the form of a web or cut sheets, or cut to sheets of a specified length downstream of the magazine, whereupon high-quality images without flaw can be obtained through the image reproduction processing including image recording, image reading and development. There is also provided as its second object an image recording medium transporting device using the guide plate assembly.
The first object stated above can be attained by a guide plate assembly of a first aspect of the invention used to transport an image recording medium having an image forming surface and guiding at least the image forming surface of said image recording medium, wherein at least a portion of a surface of said guide plate assembly opposite to the image forming surface of said image recording medium to be guided comprises:
a matrix layer;
a cushion layer formed on the matrix layer to absorb impact due to passage of said image recording medium; and
a resin layer made of a low frictional resin that is formed on the cushion layer.
In order to attain the second object, a second aspect of the invention is also provided an image recording medium transporting device to transport an image recording medium supplied from a recording medium supply section through a specified transport pathway, which comprises:
the guide plate assembly according to the first aspect; and
transport means to transport said image recording medium through said transport pathway.
In the respective aspects, said guide plate assembly guides preferably the image forming surface and a back surface of said image recording medium.
Said guide plate assembly is preferably a width guide having a U-shaped cross section and which restrains an end face of said image recording medium.
Said cushion layer has preferably at least one member selected from the group consisting of glass fibers, foamed resins, rubbers and adhesives.
Said low frictional resin is preferably a fluoroplastic material, more preferably a tetrafluoroethylenic resin.
Said image recording medium is preferably supplied from the magazine in the form of a web or cut sheets, or cut to sheets of a specified length after being supplied in the form of the web.
Said image recording medium is preferably at least one material selected from the group consisting of light-sensitive materials, copy materials, ink-jet recording materials and thermal recording materials.
Said guide plate assembly has preferably a plurality of linear bumps provided parallel to a direction in which said image recording medium is transported, or a plurality of embosses.
In the above second aspect, said transport means comprises transport roller pairs to nip and transport said image recording medium.
Preferably, said transport pathway passes through an image recording section to record an image. Said image recording section is preferably a latent image forming section where a latent image is formed on said image recording medium.
Preferably, said image recording medium is a light-sensitive material and said image recording section is an exposing section where said light-sensitive material is exposed imagewise.